I get what you're saying and I always did like the term "Serial Monogamy". One sees a lot of that in CofS as I'm sure you know, too.
That makes sense but I will say this- I have a lot of friends who've gotten divorced. In some cases, the spouse was addicted to drugs or alcohol and wouldn't get help. In others, the person lowered the boom on them, "I'm with somebody else yadda yadda". (and what's interesting is that in several cases, the person wanting the divorce tried to come back to the wife, realizing a mistake had been made and the wife was like, "I've moved on. I'm sorry, but no.") I had one friend who divorced her husband because he was a Nudist, wouldn't stop forcing it on her and she had a teenage daughter at the time. I have another friend who was divorced twice. First guy played favorites with the kids- blatantly. As in "I didn't want YOU to come over here. I wanted your brother over here." And "I never ever loved you" plus a massive amount of alcoholism and constant verbal abuse. Pregnant with their 3rd child when he really went over the line, she inwardly vowed to dump the bastard. She waited til the youngest was in school so that she could do it. Then she did.
Then she married a bank exec who, the minute they were married, changed completely. Wanked off at the breakfast table as if she weren't there, took her on a vacation trip to Ireland and proceeded to scream and bitch and howl the whole time, making her life hell. Made her sign a promissory note to his parents for the privilege of living with him.
So she divorced him.
I think a lot of people do give up too easily and I agree with you about that. But there are some people out there who are very confused, very damaged and then they get married and their spouse spends years going "What the FUCK?" til they get smart and dump them or get dumped.
So it varies.
(but you know I say that a lot!)
I'm lucky. My husband has well night super-human patience.